Multilayered amidated polymer of intrinsic microporosity for gel polymer electrolyte in lithium metal batteries

Polymers of intrinsic microporosity (PIMs) have been widely used in functional membranes in recent years because of the inefficient packing of molecules to form stable structural micropores. The gel polymer electrolyte (GPE) was fabricated with bacterial cellulose (BC) as support membrane and the partially amidated PIM-1 (named as PIM-CONH2) as functional layer, which was used as electrolyte membrane in lithium-metal batteries (LMBs). Due to the existence of amide groups, the formed PIM-CONH2/BC GPE exhibited a high Li+ transference number (0.76), good cycling performance (83% capacity retention after 200 cycles at 0.5C), and good rate recovery in a LiFePO4|GPE|Li battery. The layered porous structure in the PIM-CONH2/BC GPE could adjust the Li+ transport behavior, and the presence of an amide group promoted the uniform dissolution/deposition of Li+. And the amidated PIMs in the GPE could play a significant role in improving the interfacial affinity and suppressing the growth of lithium dendrites. This work provides a new strategy for improving the safety and stability of LMBs in order to meet the demands for functionalized LMB electrolytes.